A metrics plan must describe the who, what, where, when, how, and why of metrics.The plan begins with why, laying out the goals or objectives of the project. Next, the plan addresses what will be measured. At the same time, the plan must lay out where and when during the process the measurements will be made. How and who address the identification of tools, techniques, and staff available for metrics collection and analysis.
Thus, the metrics plan paints a compehensive picture of the measurement process from initial definition of need to analysis and application of results.
The GQM approach to process and metrics provides a structure from which managers and developers can derive a set of crucial project goals, plus the questions that must be answered in order to tell if the goals have been met.Then, each question is analyzed in terms of what measurements are needed to help decide the answer to each question. Further, the GQM approach must be supplemented by one or more models that express the relationships among the metrics.
GQM could also be combined with process assessment frameworks like The process maturity model, where an organization is rated on an ordinal scale from 1 (low) to 5 (high), based on 110 questions about its development process.
Table 13.1 lists the twelve questions required for a level 2 (repeatable) assessment; if any of these questions is answered "no", then the organization was automatically assessed at a level 1, regardless of the answers to the 98 other questions.
There were many problems with this approach and the capability maturity model (CMM) was developed to address them and replace the process maturity model.
Each of the five capability levels is associated with a set of key process areas on which the organization should focus as part of its improvement activities, see Table 13.2.